Editing Pretty Good Privacy (section)

===Digital signatures===
PGP supports message authentication and integrity checking. The latter is used to detect whether a message has been altered since it was completed (the ''message integrity'' property) and the former, to determine whether it was actually sent by the person or entity claimed to be the sender (a ''[[digital signature]]''). Because the content is encrypted, any changes in the message will fail the decryption with the appropriate key. The sender uses PGP to create a digital signature for the message with one of several supported public-key algorithms. To do so, PGP computes a [[cryptographic hash function|hash]], or digest, from the plaintext and then creates the digital signature from that hash using the sender's private key.